How Much Does a Septic Tank Cost? A Guide To Septic Systems

Aerobic Septic System Understanding Septic System Repairs

Convert to a Aerobic Septic System if you’re facing a complete replacement reduce your septic system cost. Learn how to deal with this expensive and stressful situation. Contrary to what you may have been told, there is an affordable alternative to replacing your septic system when it fails. Aero-Stream’s® patented septic remediation system can restore a failed system without costly excavation and landscaping expenses, ultimately reducing your septic system cost.

Conclusion

A new septic tank or septic system, either for new construction or an existing property, will always cost at least a few thousand dollars. The national average cost of professional installation is about $5,828, with a typical range of $3,138 to $8,518

The overall cost of the project depends on the type of septic system you use, the size of your home, and any additional services you may need to complete the installation. Though the typical price range is a good set of guidelines, keep in mind that you could end up paying as little as $1,013 or as much as $18,163

Most importantly: DON’T attempt to install your own septic tank unless you’re a professional plumber or other specialist experienced with septic systems. No matter how handy you are, no matter how much money you think you’ll save, the risk of DIY in this case isn’t worth it. 

Main Photo Credit: Andy Rogers / Flickr / CC BY-SA 2.0

Jordan Ardoin is a writer, editor, and classical literature student based in Colorado. When she isn’t reading or writing, she enjoys goofing off with her cats and spending time in nature.

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New Septic System Installation Costs

There are two main types of septic systems, conventional and alternative, with those two categories breaking down further according to how the system manages waste. An alternative or aerobic septic system typically costs between $10,500 to $15,000 on average, whereas a conventional or anaerobic system ranges from $2,500 to $5,000 with most homeowners paying $3,500 on average.

 Septic System Types And Cost   Septic System Type

Septic System Types And Cost
Septic System Type Average Cost
Conventional Systems
Gravity or Anaerobic Systems $3,500
Pressure Distribution Systems $7,000 – $10,000
Alternative Systems
Aerobic Treatment Unit $10,500
Mound Septic System $15,000
Sand Filter Septic System $6,000 – $10,000

Conventional or Anaerobic Septic System Cost

Conventional or Anaerobic Septic System Cost

An anaerobic or conventional septic system costs $3,500 to install on average with most homeowners paying between $2,500 and $5,000. These are generally the quickest, easiest, and cheapest to install, and the effluent travels through the septic tank and on into the drain field using gravity.

Aerobic Septic System Cost

Aerobic septic systems generally cost $10,500 to $15,000 on average. The aerobic system breaks down the solids in the tank using oxygen, which is accomplished using a motor and a timer. The wastewater released is cleaner than that produced by conventional systems and can be used for above-ground irrigation needs after it’s sterilized. Additional benefits include needing a drain field half the size of that of a conventional system, which allows for more placement options on your property.

Aerobic Septic System vs. Anaerobic

The main difference between aerobic and anaerobic septic systems are in how they treat the effluent. Anaerobic or gravity systems flow into a drain field while aerobic systems treat the effluent before it reaches the drain field with oxygen, biofilm in the drain tiles, or sand filters.

Mound Septic System Cost

The average cost for an above-ground mound septic system is $15,000, with annual maintenance costing as much as $500. It’s quite possible that the percolation test will come back saying that your soil isn’t of the right drainage quality to have an underground septic system, in which case you’ll have to install an above-ground septic system at two to three times the cost.

An engineered mound system is required when the soil type on the homeowner’s property is either too permeable or completely impermeable, or if there is only a shallow cover of soil over porous bedrock, or a high seasonal water table present. The purification and cleaning of the wastewater is accomplished through a biofilm present in perforated drain tiles. This slows down the water while purifying it before it reaches the water table below. As the name might imply, it will result in a raised surface or mound on your property.

Sand Filter Septic System Cost

A sand filter septic system costs between $6,000 and $10,000 to install on average. The sand filter system is like a conventional septic system, but it uses a pump to distribute the effluent to a filter system—sand housed in either a concrete or a PVC-lined box—a grid of small pipes. The sand filter allows for prefiltering of the water before it reaches the drain field to protect the underlying water table. Sand filters have been known to have a useable life of up to 20 years in some locations.

Pressure Distribution Septic System Cost

Pressure distribution septic systems range in cost from $7,000 to $10,000 on average. They only require a distance of 2’ between the bottom of the system and the water table below, and they use a pump to get the effluent to reach more of the drain field that gravity can’t accomplish unaided.

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Septic vs Sewer Cost

A septic system costs $3,100 to $9,600 to install while connecting to a main sewer line can be slightly more affordable, around $1,500 to $8,000. Think of this system as your own personal sewage system. A septic system treats wastewater on site, with an underground tank and pipe system on your property. If your home plumbing system is not hooked up to a septic system, it is connected to the main city sewer line. Sewage connections carry the wastewater from your home and route it underground to a city or county treatment plant.

SystemCost (Installed)Sewer$1,500 - $8,000Septic$3

SystemCost (Installed)
Sewer$1,500 – $8,000
Septic$3,100 – $9,600

Cost of Septic Tank Installation by Location

Conditions in your specific area such as terrain, climate, and soil type will determine the type of septic system you should use and therefore will affect the overall cost of the project. Consult a local pro to determine the best type of septic system for your area and the average cost. 

Labor costs vary by location, too. A homeowner in a metropolitan area will likely pay much more for a new septic system than one in a rural area. We’ve estimated the national average cost of labor, but the price you actually pay could be significantly lower or higher. Get at least three estimates from local pros for your septic tank project — or any home improvement project — to give you a good idea of labor costs in your area. 

Getting it Fixed

Check the websites of your local health department and state environmental agency to learn what procedures you need to follow for repairing or replacing a septic system—you may even find a list of licensed repair companies.

Call a couple and schedule visits. Or, if you have an advanced treatment system with an annual maintenance contract, call the company that’s overseeing your system already.

Get Professional Estimates for Your Septic Tank Cost Near You 

Since it’s so important to have a professional come in and design and install your septic system, you want to get a few estimates around your local area. You can start your search with the following links to help control your septic tank costs. 

Frequently Asked Questions

How Many Years Does A Septic System Last?

A newly bought and installed septic system should last for about 40 years if the tank quality and installation process are good and the system is maintained regularly.

How Often Does A Septic Tank Need To Be Pumped?

While septic tank systems vary in capacity to suit the wastewater output from your home, they are designed to be big enough to store roughly three years’ worth of sludge before needing to be emptied.

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How long does a septic tank last?

Septic tanks usually last 20 to 30 years, but some make it 40 years or more. The longevity of a septic tank depends on what they’re made of and how often they’re cleaned.

Less-popular steel septic tanks may rust out after 15 years, though many last longer. Concrete tanks have longer life spans, but they can be sensitive to acidic soil. Plastic and fiberglass tanks are less susceptible to the elements, but structural damage is more of a concern with these tanks.

The other key to longevity in septic tanks is maintenance. Regular pumping and servicing help ensure your tank does its job for years to come.

Ground Preparation

While the drain field can be expensive, it is an important part of the system. Another important element is ground preparation. You will need to clear the land, dig up the earth, and move or remove it. This costs an average of about $1,000 for a standard property and an average septic system.

Septic Tank Materials

Another factor influencing cost is what your septic tank is made from. Here are some of the most common materials:

Concrete

Concrete tanks are the most common type of septic tank because they’re durable. Properly maintained, they can last 20 to 30 years. However, concrete may crack over time. Reinforcing the concrete with rebar helps increase its strength under pressure. Installation is more challenging, and extensive equipment is needed because of its weight. According to HomeGuide, the cost for an average-sized concrete tank is between $700 and $2,000 (CAD 900 to CAD 2,600).

Fiberglass

Fiberglass doesn’t weaken when used underground, and it’s nonporous, so it won’t attract algae growth. Installation is easier because the tank is light. Unlike concrete, it won’t expand or contract, so you don’t have to worry about cracking. The average fiberglass tank costs $1,600 to $2,000 (CAD 2,000 to CAD 2,600).

Plastic

Plastic tanks are light and easy to install. They’re also quite durable. Depending on the type, plastic tanks cost $800 to $2,000 (CAD 1,000 to CAD 2,600), on average.

Steel

Despite steel’s strength and durability, septic tanks made of steel can rust and collapse if not properly cleaned. As a result, some local authorities have increased regulations to discourage their use. You’ll usually find them in areas where the system already existed. If you can get one installed, they cost $500 to $2,500 (CAD 650 to CAD 3,200), according to Remodeling Expense.

Why you need a new septic tank

AXL/Shutterstock AXL/Shutterstock

There are many reasons why you might want to replace a septic tank. These begin with a natural lifespan calculation of the current system, but this isn’t the only factor at play when it comes to replacing your wastewater treatment system.

A damaged tank should be repaired or replaced immediately

If your septic tank has been damaged or shows some of the telltale signs of leaks or other seepage issues, then inspecting the system should be your first priority. Aqua Test Inc. notes that a damaged tank can be detrimental to the surrounding ecosystem of your lawn, and the best way to catch these issues before they develop into a significant problem is to check your tank for damage every five years.

If the tank is damaged beyond repair, then an immediate replacement is simply necessary. Just like broken windows, a leaking roof, or cracks in the foundation, the septic tank is a feature of the home that can’t be pushed down the road for replacement once the time has come.

Your septic capacity needs may change over time

If you’ve recently renovated your home to include an in-law suite, added bedroom, or any other expansion to match the needs of a growing family, you may also require a larger septic tank to keep pace with your wastewater requirements. Aqua Test Inc. notes that a 900 or 1,000-gallon tank is typically appropriate for a standard layout that supports one to three bedrooms. This equates to about 500 gallons of water used per day.

Alternatively, a five-bedroom home averages about 900 gallons of water usage each day, resulting in a larger tank capacity requirement. If you’ve added new living space to support an in-law or any other new addition to the property, upgrading from a smaller tank to one that holds 1,500 gallons will help support the ongoing lifestyle and comfort that you’ve come to expect from your home.

Septic Tank Cost: Replacement Parts

As with any mechanical system, issues are bound to arise. Septic tanks that are properly cleaned and maintained can last an average of 20 to 40 years. While some of the problems with septic tank systems are easy to solve, others will require significant assistance from a professional. From baffles to tank lids, these are the most common parts of a septic tank that may need to be replaced or repaired.

Baffle Replacement

Baffles are designed to help prevent scum from clogging inlets and pipes. Baffles that fail or get clogged are a common issue, and replacing them is usually much cheaper than replacing the entire tank. Replacement costs range between $300 and $500 including labor.

Septic Tank Pump Replacement

For septic tanks that require a pump to push the effluent from the tank to the drain field, it’s possible that the pump may fail to do the job properly. The average cost to replace a failed pump ranges between $800 and $1,400 including labor.

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Tank Lid Replacement

A broken or rusted lid is a minor repair that costs between $30 and $70 before labor. Metal lids are the easiest to replace if they have rusted over, while a concrete lid may require some special equipment to remove and install the new lid.

Septic Tank Filter Replacement

Replacing a septic tank filter is the most common issue for most homeowners. The cost to have a replacement filter installed on a septic tank averages between $230 and $280.

Septic Drain Field Replacement

If a septic tank leach field or drain field becomes oversaturated, sewage can back up into the house. The average cost to dig out the existing drain field and install a new one runs $7,000.

What is a Septic System, and How Does it Work?

A septic system is an underground wastewater treatment structure most often used when a municipal sewer system is not available. They are commonly found in rural areas rather than cities.

A typical septic system consists of a septic tank, a distribution box, and a leach field. A leach field is also called a drain field or soil absorption field. A septic tank will help digest organic matter and separates floatable matter such as grease, oils, and solids from the wastewater.

The system discharges the liquid from the septic tanks into perforated pipes buried in a leech field, designed to release the effluent into the soil slowly.

Although the first septic tanks have been in use since the late 1800s, they did not become popular until the 1960s. Up until that time, a cesspool was common in most homes.

Septic Tank Repair Costs

It’s possible your entire septic tank doesn’t need to be replaced, just a specific part. Repairs and replacement parts can cost far less than a full system replacement.

Drain Field

Drain fields can overload and flood, causing a backup of sewage in toilets and sinks. Drain or leach field replacements cost $1,000 to $5,000 (CAD 1,300 to CAD 6,500), according to data from Fixr.

Tank Pump

Usually, a replacement septic tank pump costs $250 to $1,500 (CAD 320 to CAD 1,900).

Tank Filter

The tank filter is the most common replacement done by homeowners. It usually costs $200 to $300 (CAD 260 to CAD 390)

Tank Lid

Over time, concrete covers may crack, and steel lids may rust. You can typically replace a septic tank lid on your own for $150 to $500 (CAD 190 to CAD 650). It costs a bit more to have it replaced by a professional.

Tank Baffle

Baffle directs wastewater through the septic tank. Expect to pay $300 to $900 (CAD 390 to CAD 1,160) to repair a tank baffle.

How to Prepare for Your Septic Tank Installation

To ensure septic tank installation goes smoothly, here are a few tips to keep in mind.

Receive Multiple Estimates

Before any excavation or signed paperwork, receive estimates from licensed septic tank installers and read reviews about each company using trusted, third-party consumer reviews. Ensure the contractor you select holds the proper insurance and licensing and includes necessary preparations like excavation and drain field testing in their estimate.

Test the Soil and Obtain a Permit

Septic systems rely on permeable soil surrounding the tank to absorb and naturally treat liquid residue so that it doesn’t contaminate runoff water or leak into the water table. This area is known as the drain or leach field.

Before installing a septic tank, you’re legally obligated to obtain a percolation or “perc” test. This test confirms the soil meets requirements set by the city and local health department. Usually, the soil is required to have adequate amounts of permeable contents like sand or gravel. Once the land passes the percolation test, you’ll be able to obtain a permit and start the installation process.

Note: If you want to put a septic tank on a piece of land, it must pass the percolation test. We recommend ordering a test before purchasing the land you want to use for residential purposes.

Plan for Excavation

Heavy equipment is needed to excavate the large amount of land necessary for a septic tank. If you currently reside on the land, make sure to budget landscaping costs to fix any damage incurred during excavation.

If you’re building a new home, schedule the excavation at a time when it’ll have minimal impact on the construction process. Typically, this is before paving the driveways and sidewalks, but after the main frame of the home is built.

FAQs

  • How much does it cost to put in a new septic system?

The average cost of installing a septic system is between $3,100 and $9,600, including the system and installation. Anaerobic, gravity, and chamber systems are on the lower end of that average, usually costing $1,500 to $5,000. More expensive systems include the mound system, aerobic, and evapotranspiration and range anywhere from $10,000 to $20,000.

  • How much does it cost to replace a 1,000-gallon septic tank?

A 1,000-gallon tank usually costs between $800 and $2,000, but the price varies depending on the tank material. A concrete tank has the cheapest material cost, between $800 and $1,250, but it is the most expensive to transport and install because of its weight. A plastic tank is slightly more expensive, $830 to $1,400, but its weight makes it much cheaper to install, and heavy machinery is usually not needed. A fiberglass tank usually ranges between $1,600 and $2,000.

  • How many years does a septic system last?

A septic system typically lasts between 15 and 40 years. This is usually determined by the quality of the tank and the drain field. A concrete tank is extremely durable. When constructed well, it is fairly indestructible and can easily last 40 years. The lifespan of a plastic tank is about 30 years. The drain field can also be a limiting factor on the age of the system. The drain field type does not affect the lifespan of the system. However, the quality of the soil and drainage is a huge factor. Not doing maintenance on the system is one way to shorten the life of any system.

  • How many acres do you need for a septic system?

The smallest area a septic system will usually fit in is a ½-acre lot. Most homeowners with small lots opt to use an aerobic system. Most systems, such as an anaerobic or chamber system, typically need at least a one-acre lot. Mound systems need the most space because the mound itself is usually a minimum of 200 feet long.

  • Can heavy rain cause septic problems?

Heavy rain can cause problems for all types of systems because they can flood the drain field. If the drain field floods or the soil is saturated, the effluent septic water cannot effectively drain into the soil. This can cause major backups in the tank and even flooding.

  • How many loads of laundry a day are safe to do with a septic tank?

A small septic system for a two- or three-bedroom home can handle about five loads of laundry per day. This does not include any other water being used and is based on using an old washer with a 1,000-gallon tank. The washer type is a major factor because older washers can use up to 40 gallons per wash. New energy-efficient washers usually use 12 to 15 gallons of water.

  • How much does a 1,500-gallon septic tank cost?

​The average 1,500-gallon tank costs $1,300 to $2,500. This capacity is ideal for a large five- to seven-bedroom house around 3,000 sq.ft. or more. Homes with four, five, or six bathrooms can benefit from a 1,500-gallon tank, usually made of fiberglass or concrete, although plastic tanks are also available.

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